feat: 更新标签页和新增统计页面

- 修改标签页的名称和图标，将“探索”改为“统计”，并更新相关逻辑
- 新增统计页面，展示用户健康数据和历史记录
- 优化首页布局，调整组件显示，提升用户体验
- 删除不再使用的代码，简化项目结构

app/(tabs)/_layout.tsx

@@ -19,7 +19,7 @@ export default function TabLayout() {
         const routeName = route.name;
         const isSelected = (routeName === 'index' && pathname === '/') ||
           (routeName === 'coach' && pathname === '/coach') ||
-          (routeName === 'explore' && pathname === '/explore') ||
+          (routeName === 'statistics' && pathname === '/statistics') ||
           pathname.includes(routeName);
 
         return {
@@ -42,8 +42,8 @@ export default function TabLayout() {
                   return { icon: 'house.fill', title: '首页' } as const;
                 case 'coach':
                   return { icon: 'person.3.fill', title: 'Bot' } as const;
-                case 'explore':
-                  return { icon: 'paperplane.fill', title: '探索' } as const;
+                case 'statistics':
+                  return { icon: 'chart.pie.fill', title: '统计' } as const;
                 case 'personal':
                   return { icon: 'person.fill', title: '个人' } as const;
                 default:
@@ -125,34 +125,7 @@ export default function TabLayout() {
           tabBarShowLabel: false,
         };
       }}>
-      <Tabs.Screen
-        name="index"
-        options={{
-          title: '首页',
-          tabBarIcon: ({ color }) => {
-            const isHomeSelected = pathname === '/' || pathname === '/index';
-            return (
-              <View style={{ flexDirection: 'row', alignItems: 'center' }}>
-                <IconSymbol size={22} name="house.fill" color={color} />
-                {isHomeSelected && (
-                  <Text
-                    numberOfLines={1}
-                    style={{
-                      color: color,
-                      fontSize: 12,
-                      fontWeight: '600',
-                      marginLeft: 6,
-                      textAlign: 'center',
-                      flexShrink: 0,
-                    }}>
-                    首页
-                  </Text>
-                )}
-              </View>
-            );
-          },
-        }}
-      />
+
       <Tabs.Screen
         name="coach"
         options={{
@@ -182,15 +155,15 @@ export default function TabLayout() {
         }}
       />
       <Tabs.Screen
-        name="explore"
+        name="index"
         options={{
-          title: '探索',
+          title: '首页',
           tabBarIcon: ({ color }) => {
-            const isExploreSelected = pathname === '/explore';
+            const isHomeSelected = pathname === '/' || pathname === '/index';
             return (
               <View style={{ flexDirection: 'row', alignItems: 'center' }}>
-                <IconSymbol size={22} name="paperplane.fill" color={color} />
-                {isExploreSelected && (
+                <IconSymbol size={22} name="house.fill" color={color} />
+                {isHomeSelected && (
                   <Text
                     numberOfLines={1}
                     style={{
@@ -201,7 +174,35 @@ export default function TabLayout() {
                       textAlign: 'center',
                       flexShrink: 0,
                     }}>
-                    探索
+                    首页
+                  </Text>
+                )}
+              </View>
+            );
+          },
+        }}
+      />
+      <Tabs.Screen
+        name="statistics"
+        options={{
+          title: '统计',
+          tabBarIcon: ({ color }) => {
+            const isStatisticsSelected = pathname === '/statistics';
+            return (
+              <View style={{ flexDirection: 'row', alignItems: 'center' }}>
+                <IconSymbol size={22} name="chart.pie.fill" color={color} />
+                {isStatisticsSelected && (
+                  <Text
+                    numberOfLines={1}
+                    style={{
+                      color: color,
+                      fontSize: 12,
+                      fontWeight: '600',
+                      marginLeft: 6,
+                      textAlign: 'center',
+                      flexShrink: 0,
+                    }}>
+                    统计
                   </Text>
                 )}
               </View>